Efficient solution of 3D electromagnetic scattering from large homogeneous targets

Based on the combined tangential formulation of surface integral equation, a fast algo- rithm is presented for calculating electromagnetic scattering from electrically large 3D homogeneous objects. In the algorithm, the lower triangular approximate Schur preconditioner is combined with the multilevel fast multipole algorithm （MLFMA）. The coefficient matrix of the near-field coupling element is selected to set up the approximate matrix. For large problems, the incomplete LU factori- zation with dual threshold （ILUT） has better performance than sparse approximate inverse （SAI） of accelerating the convergence of the generalized minimal residual method （ GMRES ） iteration. Nu- merical experiments validate the efficiency and robustness of the presented fast algorithm for homo- geneous dielectric objects.     

Miniaturized multi-band antenna using deformed splot ring resonator

A 48mm×60mm×1mm miniaturized multi-band antenna based on deformed split ring resonators was presented.The antenna was consisted of a micro-strip line and a deformed split square ring.Its /S11/parameters were determined through numerical simulation and experimental measurement within three working bands of 2.6GHz to 3.0GHz,3.9GHz to 4.4GHz and 5.2GHz to 5.8GHz and the results showed that the parameters within all the bands were less than-10dB.The gain at every frequency for the antenna was above 2.2dB and it increased monotonously with the frequency from 5.5GHz to 7.0GHz.     

基于FDTD的二维电磁散射反演方法研究

文章针对有耗电磁介质的重建问题发展了一种新的算法.该方法在反演过程中采用常用的非线性最小二乘法来求解逆问题,通过Tikhonov正则化得到描述散射场与散射体电特性参数之间关系的迭代方程,然后将迭代方程离散化得到适于数值计算的形式,并最终实现了介质双参数的同时反演.在此基础上对有耗介质的反演进行了详细的研究,计算结果表明该方法不仅能实现介质的空间定位,在介质的电磁参数的反演上也能满足精度的要求.